The young actors of my Barbarians got a real lift on the first night last month, when a telegram arrived: "Wishing you a great run. I did the play myself when I first started out. Bet I could still do my lines. Break legs." It was from Kevin Spacey who had played the lead in the New York premiere in 1982. And when he took over at the Old Vic in 2004 I'd read – with a mixture of amazement and delight – that Barbarians was high on his list of "things to do" .

True to his word I was called to a reading of Barbarians soon after he began his tenure and I watched with real pleasure him actually mouthing all Paul's lines during the session. "This will slay them," he confidently predicted to me after the reading with a star cast in the theatre's rehearsal room but for a mixture of reasons never made clear to me the production never happened there – I suspect the subject matter wasn't quite the would-be backers cup of tea. Now it is happening in a thrilling production by Bill Buckhurst in what used to be Central St Martins School of Art with a vitality and danger more suited to the venue where the Sex Pistols played their first gig than in a theatre seeped in Shakespeare, and after that in another production at the Young Vic in November-December.

I have mixed feelings about seeing it again in two new productions: proud that the play is on in London for the first time in twenty years but also a sadness that it's a tale of a generation without hope or prospects who leave school only to join the dole queues. In fact, their plight is even worse now and I found it necessary to add one line of dialogue when the protagonist is sneering at the prospect of "doing a bint's job in a factory". He now says: "In years to come they'll call us the lucky ones for having had a choice". The stark reality is that another whole generation on Jobseekers Allowance don't have any jobs to seek. This I believe makes it a dangerous time – the combination of youthful energy and hopelessness is a powder keg waiting to explode as it does with terrible consequences at the end of the third play.

I'm excited by the forthcoming Young Vic production as it's being directed by a young woman - Liz Stevenson. It's an all male play, and having a woman direct it means totally different dynamics and view of an all-male world. Some years ago my play Sus (about the racist police interrogation of a black male, recently revived at the Young Vic) received its breakthrough production directed by a woman - Ann Mitchell. And the space of the Clare studio at the Young Vic (similar in size to the Soho Poly for which l originally wrote Barbarians) demands a chamber piece intimacy after the big spaces of St Martins.

That said, Tooting Arts Club's choice of venue is a big plus and Bill has used to great advantage the constant mobility of his actors who can literally sit at tables and speak individually to members of the audience – as though in a factory canteen. The three performances of Thomas Coombes, Jake Davies and Josh Williams nightly make the audience actually care for these kids and the confessions of dreams for the future and clumsy sequences of botched attempts to gain some money makes them worth caring about.

Go hug one of these hoodies, Mr Cameron. But keep your hands in your pockets – they have a greater need of your loose change than you do.

Barbarians, directed by JMK Award-winner Liz Stevenson, runs at the Young Vic 27 November – 19 December 2015 and Tooting Arts Club's production of Barbarians runs at the Former Central St Martins College until 7 November